In this study, I will examine the famous 'divine command theory' of Mozi. Through the discussion of several important chapters of Mozi, including Fayi (law), Tianzhi (the will of heaven), Minggui (knowing the spirits) and Jianai (universal love), I attempt to clarify the arguments of Mozi offered in support of his distinctive ideas of serving heaven, knowing the spirits and loving all. The analysis shows that there are serious problems with his assumptions, hence they fail to support his conclusions as to the heaven-human relationship, and the man-man relationship. That is to say, at least in the texts covered, Mozi did not justify the moral or social relationship in society by appealing to the religious relationship.